<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <style>
   
    .to-top{
      background:#2fa0ec;
      text-decoration: none;
      outline: none;
      width:80px;
      height:50px;
      text-align: center;
      line-height: 50px;
      border-radius: 4px;
      color:white;
    }
    .to-top:hover,.to-top:focus{color:#74777b;}
    </style>

  </head>
  <body>

    <div id="app" ></div>

  </body>

</html>
